Hello, Thanks for letting us know your health concern. I have gone through your query and would like to offer some suggestions. You are right in speculating that the emergency contraceptive pill may have caused the scanty menstruation. Yet, other causes also should be assessed, like an undiagnosed pregnancy, hormone imbalance secondary to the pill use etc. Also, please remember that there is no need to use emergency contraception during the safe period of the cycle. Hope you find this information useful. Take care.